Recipe Tip If possible, grind the mustard paste in a stone mortar-pestle. Avoid soaking the mustard in water, instead strain the mustard under running water. Share your version of this recipe Have you tried Hilsa fish curry at home? If yes, share your version of the recipe with us so that we can give it a try. Frequently Asked Questions Can I use yoghurt instead of curd? Yes. You can use Greek or low-fat yoghurt too for this recipe. What is the best alternative for mustard? You can use mustard sauce or mustard paste in place of mustard seeds.